Abrasive-feeding system for glass-grinding machines



Nov. 12, 1929. J. P. CROWLEY ABRASIVE FEEDING SYSTEM FOR GLASS GRINDINGMACHINES :s sheets-sheet A1 4Filed. DSO. 24, 1923 .Nov. 1 2, 1929. 1 P1,CROWLEY 1,735,600

ABRASIVE FEEDING SYSTEM FOR GLASS GRINDING MACHINES Filed Dec. 24, 19233 Sheets-Sheet 2 ArraqA/fri Nov. l2, 1929. J. P. CROWLEY 735y600ABRASIVE FEEDING SYSTEM FOR GLASS GRINDING MACHINES Filed D60. 24, 19,233 SheeLs-Sl'leei'I v5 ATTU/VE'Y I Patented Nov. 12, 1929uNrrlazD-s'ra'rlazs PATENT oFFlc-E f JOSEPH P. CROWLEY,

OF TOLEDO, OHIO, ASSIGNOR T0 LIBBEY-OWEN S GLASS OOM-PANT, 0F TOLEDO,OHIO, A CORPORATION 'OF OHIO ABRASIVE-FEEDING VSYSTEM FORGLASS-GRINDIN'G MACHINES Application. mea December 24, 192s.v serial No.682,495.

This invention relates to an improved'proc` l the grinding machinedisclosed in my cepending application, Serial No. 659,435, filed August27, 1923. y

According to the present invention, the new sand, or used sand which hasbeen collected from the several grinding units, is mixed with water andthen flowed through a series of grading tanks in which the abrasive isseparated into a plurality of distinct grades. Preferably, two similarseries of these tanks are'provided, and while the abrasive mixture isflowing through one series and being graded, the previously gradedabrasive in the other series of tanks may be drained off into a seriesof storage reservoirs, each reservoir being adapted to hold one grade ofabrasive and being provided with a suitable agitator maintaining theabrasive in suspension. Thiscomprises the grading system.

The feeding system consists of a series, here shown as three, of endlesspipe circuits extending past the several grinding machines. A certaingrade of abrasive is maintained 1n practically continuous circulation ineach pipe circuit, and may be drawn upon when desired to su ply the needof any one or more of the grin ing units. The abrasive mlxture incirculation in each circuit is 'replenished when necessary from thestorage reservoirs, and the abrasive mixture may be selected from anyone or a group of these reservoirs to obtain just the desired grade ofabasive for that particular circuit.

When the grinding operation of a machine is started a portion of theheaviest grade of abrasive is delivered from its pipe line to themachine. After a suitable interval this grade may be shut ofl:` and thenext finer grade fed to the machine, and so on until the grindingoperation is completed. A continuous pressure is maintained on theabrasive supply in each pipe line, which serves not only to forceplurality of plate glass the abrasive material from the pipe line tothel selected machines, but also serves to maintain the abrasive incirculation in the circuit vand keep the solid material in suspension.The used abrasive and water from the several machines How to a sump fromwhich the better part of the mixture is pumped back to the grading tanksand regraded.

The invention will be better understood from the following detaileddescription of one approved form of the apparatus. f

In the accompanying drawings:

Fig. 1 is a plan view of the entire abrasive supplying system.

Fig. 2 is an end elevation on an enlarged scale, looking from the rightof Fig. l1.

Fig. 3 is an elevation, looking from the left at Fig. 2, showing one ofthe series of grading tanks and the storage reservoirs.

Fig. 4 is a longitudinal vertical section through a portion of one'ofthe series of grading tanks.

Fig. 5 is an enlarged section through the means for draining theabrasive which hasr settled out in any single grading tank, into itsrespective storage reservoir.

Fig. 6 is a section through the series of feed pipes showing the valvesfor delivering. the abrasives to one of the grinding machines.'

Fig. 7 is an elevation, on an enlarged scale, of one of the gate valvesfor intermittently interrupting the iiow of abrasive through the pipeline, and the operating cam for this valve.

Fig. 8 is an elevation taken at right angles to Fig. 7 and on a smallerscale, showing a single driving means for the three gate valves.

The grinding machines 1, which are merely shown conventionally in thepresent drawings, may be of substantially the construction disclosed inmy prior application, Serial No.

and the used abrasive and water thrown olf from the grinding machineflow into a drain pipe 3 through wliich they pass to an underground sump4 at one end of the factory. In the installation shown in the,drawings,two opposite rows of grinding machines 1 are provided, and there is adrain pipe 3 for each row of machines, the two drain pipes leading tothe saine sump 4.

The several grades of abrasive to be used, here shown as three, althoughany desired number might be used, are maintained in circulation inthethree parallel pipe lines 5, 6 and 7, which extend past all of thegrinding units. As here illustrated, the three pipe lines extendoverhead at a point midway between the two parallel rows of grindingmachines 1. The pipe line 5 contains a supply of the heaviest sand, orother abrasive, suitably suspended in water. Pipe line 6 carries anintermediate grade of abrasive and pipe line-7 carries thevtnest grade.Asshowni'ig. 6, a. series of similar valves" 8, 9 and 10, are providedin the respective pipes 5, 6 and 7, opposite each one of the grindingmachines. These three valves are adapted to discharge into a common4basin or hopper 11, which guides the abrasive mixture into the feedpipe 2 for that particular grinding machine 1. By suitably manipulatingthe valves 8, 9 or 10, any grade'of abrasive may be fed tothe machinewhen desired. The simple form of valve here shown is adapted to bemanually operated, but automatically operated valves may be used,provided with suitable timing mechanism for feedingthe different gradesof abrasive successively to the machine for any'selected-period of time.One 'approved type of mechanism for automatically feeding the abrasivesis disclosed and claimed in my `copending application, Serial No.659,436, iiled August 27, 1923. The present application discloses animprovement on, and a con-n tinuatio'n in part of, the system disclosedin this previously liled applicat-ion.

The new sand'or other abrasive to be used i is first delivered into amixing tank 12'Wl1ere water is added and the mixture is maintained insuspension by a suitable agitator indicated at 13. This mixture isforced by pump 14 through delivery pipe 15 which has branches 16 and 17leading respectively to two similar series of grading tanks 18 and 19.The used sand from sump 4 is delivered by pump 80 through pipe 81 tothe'pipe 15, already described, from which, like the new sand, it issimilar compartments, here numbered 20 to 29, respectively. As shownmore particularly in Fig. 4, the abrasive mixture is delivered into oneend of the first compartment 20, through strainer 30, and after lowinthrough tank 20 flows over the partition 31 into the next tank orcompartment 21. While the abrasive mixture is flowing through tank 20,the heaviest portion of the abrasive will settle to the bottom of thetank, as indicated at 32. The abrasive mixture which has overtlowedwall31 into tank 21 will pass through that tank and overflow the nextpartition 33 which is somewhat lower than partition 31, into the nexttank 22, and so on throughout the series. While the mixture is flowlngthrough each successive tank, the heaviest portion of the abrasive thenremaining will settle to the bottom of that particular tank. It will be'obvious that the "deposit collected in each tank will be successivelylighter as the flow continues throughout the series from tank 20 to tank29. It will also be noted that the tanks increase in length throughoutthe group from tank 20 to tank 29, since as the abrasive re-` maininginsuspension becomes lighter, a longer time is required for it to settleout. A series of nine storage reservoirs, or makeup tanks, 34 to42,respectively, are provided, and these tanks are preferably arrangedbelow and midway between the two .series of grading tanks. Deliverypipes 43 lead downwardly from tanks 20, whereby the abrasive collectedin either or both of the grading tanks 20 may be delivered to thestorage reservoir 34. In a similar manner delivery pipes 44 lead fromthe two grading l tanks 21 to the second storage reservoirs 35,'and soon throughout the series, the next to the last grading tanks 28delivering the abrasive deposited therein to the last storage reservoir42. As shown more particularly in Fig. 5, a valve 45 is provided at theupper end of delivery pipe 43, and when it is desired to deliver intoreservoir 34 the kabrasive 32 which has settled out in tank 20, thisvalve 45 is opened. A connection 46 is provided for injecting waterunder pressure into the upper end of pipe 43 and lower end of tank 20directly above the valve 45. This is to break upthe caked abrasive whichwill be depositedat this point and permit a free flow of the abrasivethrough the valve 45 and pipe 43 to the reservoir. Water pipe 46 isprovided with a valve 47 for turning on or oit this supply as foundnecessary. It will be understood that each of the delivery pipes fromthe respective grading tanks to their respective reservoirs 1s suppliedwith a valve system similar to that disclosed in Fig. 5.

The abrasive which settles out in thel last grading tank 29 of theseries will ordinarily be too ,line for further use, and this abrasiveis drained off through ipe 48 to the sewer. The water which overows fromthe ends of tanks 29 flows back through pipes 49 and 50 to the mixingtank 12, where it may be reused with new abrasive.'

Each of the reservoirs 34 to 42, is provided with a suitably drivenagitator, such as indicated'at 51 'in tank 34, for maintaining themixture therein in suspension. A

lo water-line will also beprovided, (omitted from the drawings for thesake of clearness), leading to each reservoir for supplying thenecessary amount of liquid to the mixture therein.

The apparatus as so far disclosed, com" prises the grading system, andit will be noted that this system provides a continuously maintainedsupply of nine different grades of abrasive w ich may be drawn on k asdesired to supply the feeding system now to be described.

Adjacent the reservoir 34 is located a smaller supply-tank orservice-tank 52, which, together with the pipe circuit 5, contains theheaviest grade of abrasive mixture then in use. The abrasive is drawnout from this, service tank through pipe 53 and forced by eithery one ofthe alternative pumps 5.4 or 55, into the pipe line 5. The two parallelpumps 54 and 55 are provided so that either one may be repaired or relaced without necessitating shutting down 't e operation ofv thecircuit. This heavy grade of abrasive flows through the pipe circuit 5past all of the grinding units, and such of the abrasive as is notdrawnout through the Valves 8 and fed to certain of the machines, isreturned through the discharge end of pipe 5 back into the service-tank52, from which it o is again pumpedthrough the pipe circuit as before. Asimilar service-tank 56 for the intermediate grade of abrasive islocated between the reservoirs A36 and 37, and this grade of abrasive isdrawn from tank 56 by pumps 57, forced through pipe circuit 6 anddischarged back into the tank 56 as in the circuit first described. Athird service-tank 58 for the finest abrasive is located in the pipecircuit 7, this abrasive being forced through the pipe by the pumps 59.

g A continuous pipe 60 extends past all of the "reservoirs andservice-tanks, as shown pam ticularly in F ig. l, and branches from thispipe 60 connect with each of the reservoirs f 34 to 42, each of theservice-tanks 52, 56 and 58, and each of the pumps 54, 55, 57 and 59. Bymeans of a separate valve in each of these branches communication withthat respective tank or pump and the pipe 60 may be opened 60 or shutoff' as desired. Furthermore, there is a valve 61 in the pipe 60 betweenreservoir 36 and pumps 57, and a second valve .62 in pipe 60 betweenreservoir 39 and pumps 59. Normally, the valves 61 and 62 will beclosed. The heavier grade of abrasive is drawn into pipecircuit 5 bymeans of pumps 54 or 5 5 through pipe 60` from any one or all of thecuit 5. If it lshould be desired to use even` finer abrasive in thissystem, the valve 61 may be opened and finer grades of abrasive obtainedthrough pipe 60 from any of the reservoirs 37 to 39. However, thereservoirs 34 to 36 will ordinarily supply the pipe 5,

and valve 61 will remain closed. As pre-vvv viously stated, the abrasivein pipe line 5,

which is not delivered to any of thegrinding' machines 1, 'returnsjfromthe outlet end of pipe 5 into the service-tank 52 from which it is againdrawn through valve outlet 53 into the supply end of pipe line 5. Ofcourse the supply of abrasive in the pipe line 5 and service-tank 52will gradually be used up as this supply is drawn upon by the variousgrinding machines, and the supplymay be replenished as often as foundnecessary by drawing upon any .one or all of the reservoirs 34 to 36, aspreviously described.

In an exactly similar manner the intermediate grade of abrasive whichiows through pipe line 6 and supply reservoir 56 is replenished from theabrasive stored in reservoirs 37, 38 and 39. If desired, finer abrasivemay be drawn into this system from reservoirs 40, 41 or 42, by openingthe normally closed valve 62 in pipe 60. In an exactly similar mannerthe finestI grade of abrasive in pipe line 7 and service-tank 58 issupplied from the abrasive stored in reservoirs 40, 4l and 42.

l An overflow pipe 63 (see Fig. 2) extends past all of the resevoirs andservice-tanks with branches opening into the upper ends of each of thesetanks. This pipe 63 discharges into the sump 4. In this way any excessof abrasive mixture in any of t-he service-tanks or reservoirs will liowback to the sump. To avoid confusing the drawings this pipe is not shownin Figs. l and 3.

At a convenient point in each of the pipe lines 5, 6 and 7, near itsdischarge end is located a cut-off valve 64, preferably of the gate typeas shown in Figs. 7 and 8. The operating stem 65 of each valve has a pin66 traveling in the cam slot 67 of a large rotary cam 68, keyed on ahorizontal drive shaft 69. As shown in Fig. 8, the three cams may all beconveniently mounted on the Asame drive shaft 69, which is driventhrough suitable reduction gearing 70 from a motor7l. When v pin 66 isin the outerportion of the camslot 67 the valve is closed, but when thepin is in the inner portion of the cam the valve is open.

These gate valves 64 will be intermittently opened or closed by themechanism just described. We will"describe the operation of the heavierabrasive in pipe line 5, although an exactly similar cycle of events 1ss1multaneously but independently taking place in each ot the pipe lines6 and 7. `Since the pump 54 or 55 is constantly operating, a pressure isbeing putupon the abrasive mixture in the pipe line, tending to keep acontinuous How through the pipe. When valve 64 is open this flow mayproceed through the circuit and back to service-tank 52, although someof it may flow through such of the valves 8 as are open at this time.When valve 64 is closed, the flow through the pipe or conduit back tothe service-tank 52 is cut off and the only outlet for the abrasive, nowunder considerable pressure from the pump, is through the open valves 8.In this way a positive ilow of abrasives through all of the Valves 8then open is insured, and there will be sulicient force behind this flowto blow out any valve'that may tend to become plugged by an accumulationof abrasive. The intermittent low through the pipe line, during theintervals when the valve 64 is open, will serve to kee the abrasive insuspension in the pipe. uch abrasive as passes by the lvalve 64 duringthese intervals Hows back to service-tank 52 and is ready for a new'ourney through the pipe line. As stated a ove, the same cycle ofoperations is independently taking place in each of the other pipe lines6 and 7 It will be noticed that while a complete installation isdisclosed for grading abrasive, feeding the selectedgrades of abrasivetothe grinding machine, and regarding the used abrasive, this systemcomprises two simultaneously operating, but independent, systems, i. e.,a grading system for providing and maintaining a constant supply ofvarious grades of abrasive, from which the abrasives to be used may beblended; and a separate feeding system for maintaining certain selectedgrades of abrasive in circulation past the several grinding machines.

In the grading system new abrasive or used abrasive may be independentlyor simultaneously delivered to either or both of two in- 'dependentseries of grading tanks. Preferably, the grading process will be carriedon alternately in these two series of tanks, theabrasive previouslygraded in one series of tanks being drained off into the storagereservoirs while the grading operation is being carried onsimultaneously in bot-l1 series of tanks, or, if there is suiiicientabrasive on hand or it is desired to clean or repair the grading tanks,the grading operation may be entirely discontinued for a period withoutinterfering with the continuous flow! of abrasive in the feeding systemwhich is replenished from the storage reservoirs. The several grades ofabrasive are stored and maintained in suspension ready for use in theseries of storage reservoirs 34 to 42, and the three selected grades ofabrasive for use in the machines may be varied and replenished asdesired from these reservoirs.

A system quite similar to the above may be used in the polishing room tofurnish one or more grades of rouge to each of the polishing machines.It is contemplated that such a system, with rouge used instead ofabrasive, shall be within the scope of the following claims.

Claims:

1. In a system for supplying abrasive to a plurality of grindingmachines, means for maintaining a circulation of the abrasive past theseveral machines, means at each machine permitting withdrawal of aportion of the abrasive when desired, a series of storage reservoirs fordifferent grades of abrasive, means permitting selective replenishmentof the circulating system from these reservoirs, and a series of gradingtanks for supplying the reservoirs. f

2. In a system for supplying abrasive to a plurality of grindingmachines, means for maintaining a circulation of the abrasive past theseveral machines, means at each machine permitting withdrawal of a.portion of the abrasive when desired, a series of ystorage reservoirsfor different grades of abrasive, means permitting selectivereplenishment of the circulating system from these reservoirs, a seriesof grading tanks for supplying the reservoirs, and means for returningthe used abrasive to the grading tanks.

3. In a system for supplying abrasive to a plurality of grindingmachines, .means -for maintaining a circulation of the abrasive past theseveral machines, means at each machine permitting withdrawal of aportion of the abrasive when desired, a series of storage reservoirs fordii'erent grades of abrasive, means permitting selective replenishmentof the circulating system from these reservoirs, a series of gradingtanks for supplying the reservoirs, and means for feeding new abrasiveto the grading tanks.

4. In a system for supplying abrasive to a plurality of grindingmachines, a supply tank for the abrasive mixture, a conduit eX- tendingin proximity to the several-machines, means for circulating abrasivefrom the supply tank through the conduit and returning the unusedabrasive to the supply tank, means -at each machine permittingwithdrawal of abrasive from the conduit as desired, a series of storagereservoirs for different grades of abrasive, means permitting selectivereplenishment of the circulating system from these reservoirs, and a.series of grading tanks for supplying the reservoirs.

5. In a system for supplying abrasive to a plurality of rindingmachines, a supply tank for the a rasive mixture, a conduit extending inproximity to the several machines, means for circulating abrasive fromthe supply tank through the conduit and returning the unused abrasive tothe supply tank, means -at each machine permitting withdrawal ofabrasive from the conduit as desired, a series of storage reservoirs fordifferent grades of abrasive, means permitting selective replenishmentof the circulating system from these reservoirs, a series of gradingtanks for supplying the reservoirs, and means for returning the usedabrasive to the grading tanks.

6. In a system for supplying abrasive to a plurality. of grindingmachines, a plurality of supply tanks for different abrasive mixtures,conduits extending from each tank past the several machines, and meansfor circulating the abrasive mixtures through the conduits and returningthe unused abrasives to the respective supply tanks, means at eachmachine permitting withdrawal of abrasive as desired from any conduit, aseries of storage reservoirs for different grades of abrasive, meanspermitting selective replenishment of the different grades of ciculatingabrasive from certain of these reservoirs, and a series of grading tanksfor supplying the reservoirs.

. 7. In a system for supplying abrasive to a the respective supplytanks, means at each machine permitting withdrawal of abrasive asdesired from any conduit, a series ofstorage reservoirs for differentgrades of abrasive, means permitting selective replenishment of thedifferent grades of circulating abrasive from certain of thesereservoirs, a series of grading tanks for supplying the reservoirs, andmeans for returning the used abrasive to the grading tanks.

,8. In a system for supplying abrasives to grinding machines, means forgrading the abrasives, means forseparately storing the graded abrasivesin suspension in a liquid, means permitting selective combining of thevarious grades to obtain the desired grade for use, means forcontinuously, circulating this selected abrasive to and past the severalmachines, and means permitting selective delivery of portions of thiscirculating abrasive to any machine.

9. In a system for supplying abrasives to grinding machines, means forgrading the abrasives, means for separately storing the graded abrasivesin suspension in a liquid, means permitting selective combining of thevarious grades to obtain the desired gradeffor use, means forcontinuously circulating this selected abrasive to and past the severalmachines, means permitting selective delivery of portions of thiscirculating abrasive to any machine, and means for gradin the usedabrasivev and returning it tov t e storage means.

10.v In an apparatus to supply abrasives to inding mechanism, a seriesof grading tan s through which abrasive in suspension flows, a series ofstorage reservoirs into which the graded abrasives deposited in thegrading tanks'are withdrawn, means for feeding abrasive to the grindingmachines, and means permitting selective drawing from certain of thestorage tanks to supply the desired grade of abrasive to the feedingmeans.

11. In an apparatus to supply abrasives to grinding mechanism, a seriesof grading tanks through which abrasive in suspension flows, a series ofstorage reservoirs into which the graded abrasives deposited in thegrading tanks are withdrawn, the reservoirs being divided into aplurality of groups, means for feeding abrasive from each group to thegrinding machines, and means permitting selective drawing from anyreservoirs in a` group to supply the desired grade to that feedingmeans. Y

12. An apparatus for supplying abrasive to sheet surfacing machines,comprising a supply tank, a conduit extending from the tank past themachines and discharging back mto the tank, means for forcing abrasivethrough the conduit, means for feeding abrasive from the conduitselectively to the` machines, a series f reservoirs for different gradesof abrasive in suspension, means permitting replenishment of theabrasive circulating in the conduit and tank from the reservoirs, aseries of grading tanks, means permitting discharging ofthe gradedmaterial from the grading tanks into the reservoirs, and means forconductin the used abrasive from the machines to t e grading tanks.

13. In an apparatus for supplying abrasives to grinding mechanisms, twoseries of grading tanks, means for alternately feeding abrasives insuspension to either series, a series of storage reservoirs into whichthe graded abrasives are withdrawn, a circulating system for feedingselected grades of abrasive to the grinding mechanisms,` and meanspermitting replenishment of the circulating system from the reservoirs.

14. In an apparatus for supplying abrasives to grinding mechanisms, twoseries of grading tanks, means for alternately feeding abrasives insuspension to either series, a series of storage reservoirs into whichthe graded abrasives are withdrawn, a circulating system for feedingselected grades of abrasive to the grinding mechanisms, means permittingreplenishment of the circulating system from the reservoirs, and meansfor returning the abrasives used on the grinding machines to thegrading-tanks.

i 15. An apparatus for supplying abrasive a series of grading tanks,means for discharg' yto a sheet-surfacing machine, comprising a supplytank and a conduit leading from the tank past the machine and back tothe tank, means for permitting abrasive to be fed from the conduit tothe machine, means for maintaining a continuous pressure l011 theabrasive in the conduit, a valve for intermittently closingcommunication. between the discharge end of the conduit and the tank, a.series of reservoirs for different grades of abrasive in suspension, andmeans permitting replenishment from the reservoirs the abrasive supplycirculating in the tank and conduit.

' 16. An apparatus for supplying abrasive to a sheet-surfacing machine,comprising a supply tank and a conduit leading from the tank past themachine and back to the tank,

means for permitting abrasive to be fed from the conduit to the machine,means for maintaining a continuous pressure on the abrasive vin theconduit, a valve for intermittently closing communication between thedischarge end of-the conduit and the tank, a serles 4of reservolrs fordifferent grades of t abrasive 1n suspens1on, means permittlngreplenishment from the reservoirs the abrasive supply circulating in thetank and conduit, a series of grading tanks and means for discharginggraded abrasive from the grading tanks into the reservoirs.

17. An apparatus for supplying abrasive to a sheet-surfacing machine,comprising a supply tank and a conduit leading from the tank past themachine and back to the tank,

means for permitting abrasive to be fed from the conduit to the machine,means for maintaining a continuous pressure on the abrasive in theconduit, a valve for intermittently closing communication between thedischarge end of the conduit and the tank, a series of reservoirs fordifferent grades of abrasive in suspension, means permittingreplenishing from the reservoirs the abrasive supply circulating in thetank and conduit,

ing graded abrasive from the grading tanks into the reservoirs, andmeans for conducting used abrasive from the machine to the gradingtanks. Y

igned at Toledo, in the county of Lucas and State of 0hio, this 21st dayof December, 1923.

JOSEPH P. CROWLEY.

